public static int getZ(ItemStack stack) {
   return ItemNBTHelper.getInt(stack, "posz", 0);
 }
 public static int getY(ItemStack stack) {
   return ItemNBTHelper.getInt(stack, "posy", -1);
 }
 public static void setY(ItemStack stack, int y) {
   ItemNBTHelper.setInt(stack, "posy", y);
 }
 public static void setZ(ItemStack stack, int z) {
   ItemNBTHelper.setInt(stack, "posz", z);
 }
 public static void setX(ItemStack stack, int x) {
   ItemNBTHelper.setInt(stack, "posx", x);
 }